1. Field of the Invention
This invention relates to controlling signal processing.
2. Description of the Prior Art
It is common for signal processing apparatus to be operable in a number of signal processing modes. An example of such an apparatus is a video down-converter which can receive an input video signal in, say, an 1125 line or a 1250 line high definition video format and generate an output video signal in, say, a 525 or a 625 line conventional definition format. The various possible modes of operation, in addition to the simple choice of line format, might include a selection between a horizontal line cropping mode and a horizontal spatial compression mode to cope with the different aspect ratios of the input and output signals, and a selection between a full screen and a "letterbox" mode for the output video signal.
Accordingly, an apparatus of this type can have many different modes of operation, possibly with a normal or default mode applying if no other mode is positively selected.
In the case of a signal processing apparatus of the type described above, it is then necessary to ensure that the appropriate signal processing coefficients (e.g. filter coefficients and various other signal processing parameters) are passed to signal processing devices within the apparatus.